The present invention relates generally to autism and specifically to a method for treatment of the symptoms of central nervous system disorders including autism, multiple sclerosis (MS) and attention deficit disorder/attention deficit as hyperactivity disorder (ADD/ADHD).
Autism is a profound and poorly understood developmental disorder that severely impairs a person's abilities, particularly in the areas of language and social relations. The disabilities of autistic children in language and communication range from mild to profound. In many cases the disorder is evident during the first 30 months of life. Autistic children are normal in appearance, physically well developed and are usually boys (by a ratio of 3:1).
The most distinctive feature of autistic children is that they appear isolated from the world around them and may appear detached, aloof, or in a dreamlike world. Autistic children often appear only vaguely aware of others in their environment, including family members, and frequently display unusual mannerisms and engage in ritualistic behavior. Appropriate play with other children or toys is uncommon and there is often a great interest in inanimate objects, especially mechanical devices and appliances. Historically, children were frequently institutionalized by the ages of nine or ten because their parents were no longer able to control them. While, the availability and effectiveness of behavioral support services and advances in treatment and education of treatment of children with autism have reversed the trend toward institutionalization autistic children still require significant resources for their care.
There are no medical tests that can be used to determine autism. Instead, the diagnosis of autism is made when a subject displays six of 12 characteristic behaviors that match the criteria in the Diagnostic and Statistical Manual, Fourth Edition (DSM IV), published by the American Psychiatric Association. Subjects with autism, compared to other disabled persons of commensurate ability, are more difficult to teach and comparatively have significantly greater problems acquiring and using language and relating socially. Historically, about 75 percent of subjects with autism are classified as mentally retarded.
Autism was first described by Dr. Leo Kanner, a psychiatrist at John Hopkins University in the 1940's who examined a group of 11 children who were self-absorbed and who had severe social, communication, and behavioral problems. It was originally believed that subjects with autism had good cognitive potentialities and that autistic children possessed latent genius that could be unlocked by discovery of the appropriate key for that child. Associated with that belief was the misconception that autism was caused by parent's behavior and particularly was the result of "cold" mothers whose projection of hopelessness, despair and apathy was projected onto their children.
More recently, this psychoanalytic view of autism was replaced by a neurologically based approach and continuing study as to the organic causes of the disease. Of interest to the present invention is the observation that the incidence of autism may be increasing in the population in the United States and other developed countries. In a recent report to the state legislature, the California Department of Developmental Services has described a three-fold increase in the number of persons with autism statewide between 1987 and 1998 and a doubling of the percentage of total mental health client population accounted for by persons with autism during that time. Similar observations have been made elsewhere in the United States and in other developed countries.
Much speculation concerning the apparent increase in the incidence of autism has focused on possible links between immunological causes of the disease. Prenatal and postnatal infections have been implicated as possible causes of autism. In particular, congenital rubella and HSV infections have been associated with incidence of autism.
Links between a family history of autoimmune disorders such as type 1 diabetes, adult rheumatoid arthritis, hypothyroidism and systemic lupus erythematosus have also been observed with the occurrence of autism suggesting that immune dysfunction may interact with various environmental factors to play a role in autism pathogenesis. Journal of Child Neurology, vol. 14, number 6 pp. 388-394 (June 1999).
Other workers have reported an association between autism and the presence of antibodies against human herpes virus-6, as well as autoantibodies against tissues of the central nervous system such as myelin basic protein (MBP). See Warren et al. Neuropsycholobiology 34:72-75 (1996).
In addition, Asperger, "Die Pyschopathologie des coeliakakranken kindes." Ann, Paediatr 197: 146-151 (1961) reported an association between intestinal dysfunction and autism. Other studies including those of Walker-Smith et al. Lancet ii: 883-84 (1972) and D'Eufemia Acta Paediatrica 85: 1076-79 (1996) which show low concentrations of alpha-1 antitrypsin and abnormal intestinal permeability respectively suggest that the consequences of an inflamed or dysfunctional intestine may play a part in behavioral changes in some patients.
Recently, attention has focused on the possibility of an association between childhood vaccinations and autism. Both, infection and the immune reaction resulting from immunization would be consistent with an immunological cause of the disease. In particular, the combined measles, mumps, and rubella (MMR) vaccine, rather than the monovalent measles vaccine, has been associated with the onset of autism. See Gupta Proc. Natl. Autism Assn. Chicago 1996, 455-460. This observation has led to the suggestion that some form of immune overload may constitute an aspect of susceptibility to measles vaccination. As a consequence, some workers in the field have suggested a suspension of administration of the combined MMR vaccine in favor of sequential administration over time of the three vaccine components.
Wakefield et al. Lancet 351: 637-641 (1998) identified a chronic enterocolitis in children related to neuropsychiatric dysfunction and autism. In most cases, the onset of symptoms occurred after immunization with the MMR vaccine. While Wakefield et al. stated that they had not proven an association between MMR vaccine and the syndrome described they suggested that ongoing virological and epidemiological studies might resolve the issue. At that time, Wakefield et al. suggested that the published evidence was inadequate to show whether there was a change in incidence or a link with MMR vaccine. But see, Peltola, et al. Lancet 351:1327-1328 (1998) which reported work in which children who received the MMR vaccination in Finland between 1982 and 1996 were traced but failed to find support for the suggestion that the vaccination could cause autism or bowel disease. Additional work by Wakefield and others indicates that there exists live measles (rubeola) vaccine virus in the guts of the vast majority of autistic children and that autistic patients often have a serum antibody titer to rubeola virus hundreds of times higher than normal, suggesting continual or oft-repeated exposure and/or incomplete or failed elimination of the virus by the human response. Significantly, if rubeola virus were present in the gut, as suggested by photomicrographs by Wakefield, such virus particles would be protected from the body's immune defenses because antibodies do not generally travel from the circulatory system to the lumen of the intestinal tract. Accordingly, massive numbers of circulating antibodies may be of no real protective value against rubeola virus in the gut.
While the possibility of a link between MMR vaccination and autism has prompted suggestions that measles vaccine be applied singly rather than as a component of a multi-component vaccine as a means for reducing the incidence of autism there remains a need for method of treating the symptoms of autism in subjects who already affected by the condition.
Multiple sclerosis (MS) is a slowly progressing demyelinating disease of the central nervous system which is insidious and characterized by multiple and varied neurological symptoms characterized by remissions and exacerbations. The onset of the disease usually occurs between 20 and 50 years of age with a peak occurring in people 30 years old. MS is believed to be immunological in nature but treatment with immuno-suppressive agents is not advised. The prevalence of MS varies widely with location with the highest prevalence found at higher latitudes in the northern Europe and northern North America. The geographic variation suggests that MS may in part be caused the action of some environmental factor that is more common at high latitudes. The prevalence of MS in some ethnic groups and its low incidence and near absence in other ethnic groups suggests a genetic influence on susceptibility. Twins studies and other familial studies confirm that susceptibility to MS is at least partly genetic. While the genetic factors that confer susceptibility to MS are only partly known the human leukocyte antigen (HLA) class II DRB1*1501 haplotype has been found to be reproducibly associated with MS.
The evidence for MS being an autoimmune or an immune-mediated disease includes the pathologic findings of plaques in the myelinated fibers, an increased synthesis of IgG in the cerebrospinal fluid, and various abnormalities of leukocyte function. The autoimmune response could be either the primary cause of the disease of an epiphenomenon of other disease processes. According to one theory, an autoimmune attack on myelin is precipitated by an infectious organism that contains a protein similar to a myelin protein. Infection by the organism then elicits a vigorous immune response from lymphocytes that recognize the cross-reactive protein and thereby also attack the myelin.
Treatment of MS can be classified in terms of treatment of acute relapses, the prevention or relapses and the management of symptoms. Acute relapses are typically treated with oral prednisone and with dexamethasone while interferon beta has shown potentially promising results in the prevention of relapse. Glatiramer which is a synthetic random polymer of four amino acids also shows promise in reducing the frequency of relapses in MS. While its mechanism is not definitively established it is believed that it binds to MHC class II antigen and induces organ-specific T helper 2 cell responses. Many symptoms of MS such as depression, fatigue, spasticity, bladder dysfunction and pain are treated by conventional means. Of interest to the present invention are the disclosures of McMichael U.S. Pat. No. 4,521,405 which discloses a method for alleviating the symptoms of multiple sclerosis comprising the administration of inactivated attenuated measles virus. Nevertheless, despite the known therapies there remains a desire in the art for new and improved methods for treatment of multiple sclerosis.